The Project’s mineralization is a low to intermediate sulfidation epithermal system with silver, lead, and zinc deposits hosted in stock works, breccia veins, and fractures. The gold zone to the south is a low sulfidation epithermal gold occurrence in association with silica. The antimony zone is comprised of stibnite-pyrite veins with silica. There is also sulfide mineralization in the sediments that are essentially barren of silver and lead.

The above combinations are indicative of the epithermal mineralization that is sometimes associated with distal zoning around a porphyritic intrusion.

Mineralization at the Corani Project occurs in three distinct and separate zones: Corani Main, Corani Minas, and Corani Este, each differing slightly in character with regard to both alteration and mineral assemblages. In general, mineralization in outcrop throughout the Corani Project is associated with iron and manganese oxides, barite, and silica. Silicification is both pervasive and structurally controlled along veins. In drill core, the mineralization occurs in typical low to intermediate sulfidation Ag-Pb-Zn mineral assemblages.

The most abundant silver-bearing mineral is fine-grained argentian tetrahedrite or freibergite (Hazen Research Inc., 2006; Gunning, 2007). Other minor silver minerals present include acanthite and the lead-silver sulfosalts, adorite and diaphorite. Other sulfide minerals include pyrite-marcasite, boulangerite, sphalerite, and galena. Boulangerite and galena do not appear to be significant hosts for the silver. Sphalerite, mainly high Fe type, overlaps the silver mineralization but can be more areally extensive, particularly at Corani Minas, where sphalerite may extend 10 to 100 m beneath and lateral to the silver-bearing minerals. Lead also occurs as plumbogummite, a lead-aluminum phosphate. Lead mineral speciation is dependent on pH, and the plumbogummite is believed to be secondary in origin, forming as a result of the remobilization of lead in the presence of phosphate in a very acidic environment with abundant aluminum.

Corani Main
The primary mineralized vein breccia in the Corani Main area can be traced for 800 m and undulates with strikes and dips varying between S50°E, 55°W and S20°W, 40°W, with steepening dips to the north. Vein breccias locally attain widths of greater than 10 m. To the north, strike and dip change, which indicates a plunging, dilatant structure that attains widths of 80 m, with nearvertical quartz veins surrounded by stockwork systems in adjacent wall rock. The change in strike suggests that an overall sinistral (left-lateral) strike-slip component affects the veining, causing the mineralization to blow-out, or widen and intensify, to the north (Nelson, 2006). Breccias and stockworks are characterized by chalcedonic, cockscomb, crystalline, hyaline, and amethystine quartz, with hematite-jarosite-goethite and barite stringers resulting in a highly banded texture. Manganese oxides are generally sparse but locally abundant. Pyrite, dark sphalerite, and freibergite are present (Petersen, 2005; Espinoza, 2006). A post-mineral transverse fault, striking N70°E and showing dextral movement, separates the Corani Main and Corani Minas mineralized areas. The fault deforms the veins on either side; however, post-mineral displacement appears minimal, despite the fault’s appearance as a major lineament.

Corani Minas
Corani Minas is structurally complex and characterized by a large area of small, crested ridges formed by breccias, silicification, and quartz vein ribs. Veins, 0.1 to 2.0 m wide, are composed of banded, chalcedonic, and hyaline quartz, barite, hematite, jarosite, goethite, pyrite, and proustitepyrargerite. The veins generally strike north 20°-60° west with 50° to 80° dips to both the west and east (Desrochers, 2005; Nelson, 2006; Prado, 2008), although almost any dip angle can be observed (Nelson, 2006). Hanging-wall breccias are composed mainly of subrounded to angular clasts with void-filling barite crystals in a siliceous matrix, whereas stockwork veining is mainly within the footwall. According to Nelson, orientations and textures, such as the absence of slickensides, indicate that veining was extensional and that block rotations tended to occur surrounding an east-west axis.

Corani Este
Corani Este is distinct in that mineralization is controlled by a single listric fault that does not crop out due to post-mineral tuff cover. Silicified breccias and stockwork veining are formed in the hanging wall of the main vein and crop out as silica-rich ribs along a north-south strike. Dips are difficult to determine in outcrop and drill core due to the structural complexity and hydrothermal alteration; however, conjugate vein sets, occasionally north-south striking and dipping both east and west, are observed. Importantly, a small breccia pipe occurs in Corani Este containing highgrade silver values (=300 g/t silver). Mineralization within the pipe occurs in hydrothermal breccias with a dark-gray, sulfide matrix and dark-purple, jasperoid vein breccias.

The Corani Project will be mined using conventional open pit mining methods, with either an owner mining or a contractor mining scenario. The base case assumes contractor mining. The rock will be broken by drilling 0.156 m diameter blast holes and blasting with ammonium nitrate/fuel oil (ANFO) and emulsion. Broken rock will then be loaded into 140 tonne trucks using a 19 cubic meter (m3) front end loader or one of two 22 m3 hydraulic shovels. Support equipment includes two Caterpillar D9 bulldozers, a road grader, water trucks, rubber tire dozer, compactor, excavator, fuel and lube trucks, and other miscellaneous equipment.

The mine plan considers extraction of the proven and probable ore material included in the mineral reserve presented in Section 15. The mine plan has been developed to deliver 9,855 kt of ore per year (27,000 t/d x 365 processing days) to the crusher for processing by flotation to produce two concentrates: lead-silver, and zinc-silver.

Drilling
Drilling will be carried out using drill rigs equipped with down-the-hole hammers. Based on the rock hardness documented in the report “Corani Blast Fragmentation Project, Topex” (2015), the rock is of low to medium hardness with an unconfined compressive strength ranging between 27.5 MPa and 36.9 MPa. The drill pattern selected allows for a powder factor of 0.26 kg/t, consistent with the requirement documented by Topex.

Drilling will be conducted using two Atlas Copco DM45 drills, with 156 mm diameter holes. A third drill will be required during the mine life. The third drill selected is an Atlas Copco ROC L8 and will drill between 76.2 mm to 127 mm diameter holes. This drill has been selected as it can also be utilized for drilling of wall control holes, secondary basting, and probe drilling to confirm locations and safe cover of underground workings.

Blasting
Blasting activates will be undertaken by the mining contractor with either their own specialist team in blasting or utilizing a sub-contractor. In either scenario the contractor will provide the explosives and a “down-the-hole” service, whereby the contractor is responsible for designing drill patterns (with approval by the client), priming, loading, and firing of each blast. As some holes will be wet (rainfall and ground water), it is estimated that 50% of blasting will utilize ANFO (for dry holes) and 50% will utilize a waterproof blend of emulsion and ANFO. Explosives will be loaded into drill holes using a Mobile Mixing Unit Truck provided by the contractor. Blasting is expected to be conducted on average three times per week. All personnel within a radius of 500 m of the blast must be evacuated during firing time, as required by the Peruvian mining regulations.

Blasting accessories to be used include boosters (1 lb), downhole non-electric detonators, surface delay non-electric detonators, detonating cord, and non-electric lead-in line. To ensure acceptable blasting performance, crushed stemming will be used.

Loading, hauling, and ore rehandling
In addition to the mining requirements, some ore will need to be re-handled to the primary crusher from the short-term stockpiles (located within the East Pit limit), during the mine life.

Production loading will be undertaken using two Caterpillar 6040FS face shovels, loading Caterpillar 785D dump trucks. A Caterpillar 994F front-end loader will also be required for loading of stockpiled ore into the dump trucks and to allow loading activities to start up again quickly after blasting.

One caterpillar 994F front-end loader will be required for re-handle of ore. The front-end loader will work over the life of the mine.

Ancillary work and equipment
Typical ancillary activities will be required to support drilling, loading and hauling activities. These include maintaining floors in the loading and unloading areas, scaling pit walls, construction of temporary ramps and accesses, maintaining haul roads, spreading waste, profiling the external faces of the DDMR and maintenance of short-term ore stockpiles.

A cost-effective plant has been designed to process the Corani ore at a rate of 27,000 t/d. This was achieved by minimising the footprint, maximising throughput and taking advantage of the topography.

The mined ore will be crushed by a single gyratory crusher prior to two stages of grinding in a semi-autogenous (SAG) mill and ball mill.

Primary crushing
Run-of-mine (ROM) ore (F100 of 1000 mm) will be delivered using 135-140 t trucks (CAT 785) and fed into the crushing circuit via a single dump hopper with 240 t live capacity. The dump pocket is designed to allow truck dumping from one side. Using a single truck dump design reduces the ROM area and associated earthworks, improves maintenance accessibility and reduces operating complexity.

Ore will be crushed using a 50’ x 65’ gyratory crusher, with a closed side setting (CSS) of 120 mm,
and discharged via a belt feeder onto the crushed ore sacrificial conveyor (38 m) and transferred
onto the overland conveyor (650 m). The sacrificial conveyor is equipped with a metal detector to
detect tramp metal. The conveyor will stop if tramp metal is detected and an operator will use an
overhead hoist to remove the tramp metal. The overland conveyor will be fitted with a
weightometer to monitor crusher production/stockpile feed rates.

Auxiliary crusher equipment includes lubrication, hydraulic and cooling systems, dust seal blower and grease barrels and dosing equipment as well as the rock breaker and its hydraulic pack.

Coarse ore stockpile and reclaim
The overland conveyor will feed the crushed ore to a single conical coarse ore stockpile. The feed to the stockpile is launched from a ridge to reduce concrete, steel and bulk earthworks. The stockpile will have a total storage of approximately 49 000 t. The live capacity was estimated to be only 7% of the total stockpile capacity, with the remaining capacity able to be recovered with earthmoving equipment. The Jenike and Johanson flow property test results for crushed ore (received in May 2019) indicated a strong tendency for the ore to form stable ‘ratholes’ that reduces the likely live capacity. This will be managed by use of a dozer or excavator on the stockpile when ore is not be crushed to the stockpile. The stockpile will provide surge capacity between the primary crusher and the process plant for ROM ore tonnage fluctuations and maintenance activities.

Coarse ore will be reclaimed from the stockpile by two variable-speed drive apron feeders. Each feeder will have capacity to provide 100% of the full base case tonnage rate to the SAG mill, but will generally operate at 50% capacity for even draw down of the stockpile.

The apron feeders will discharge onto the SAG mill feed conveyor. Coarse ore, combined with pebble recycle, will be transported to the SAG mill feed chute.

The SAG mill feed conveyor will be fitted with a weightometer, prior to pebble recycle conveyor discharge, to measure new feed rate for process control and metallurgical accounting.

Grinding and classification circuit
The grinding circuit was designed using ore characterization tests that determined Bond crushing, rod and ball mill work indices of 9.0, 11.8 and 14.7 kWh/t, respectively, and a JK SMC test (Axb) result of 80. The grinding circuit will consist of a SAG mill, and a ball mill operating in closed circuit with a cyclone cluster. The product from the grinding circuit (cyclone overflow) will have a nominal density of 32% w/w solids. The P80 will vary as a function of ore hardness, say between 70 µm and 120 µm based on the life of mine (LOM) ore hardness data available from
test work.

The SAG mill feed conveyor will transfer reclaimed ore at a design rate of 1223 t/h (dry) to the SAG mill feed chute where it will be combined with dilution water, grinding media and lime slurry. The (7.92 m diameter x 7.32 m EGL) is provided with a slip energy recovery (SER) hyper-synchronous drive through a single pinion.

The SAG mill is fitted with a trommel screen equipped with water sprays to separate slurry and coarse unbroken rock or pebbles. SAG mill trommel undersize will gravitate to the cyclone feed hopper where it will be combined with the ball mill trommel undersize. The trommel oversize (pebbles) will be transported by a pebble recycle conveyor which transfers the pebbles to the SAG mill feed conveyor. Pebbles can be discharged into a bypass bunker by a diverter gate as required.

Slurry from the cyclone feed hopper will be pumped to the primary cyclone cluster (24 hydrocyclones each 500 mm diameter). The cyclone underflow stream will report to the ball mill feed chute. The ball mill will operate in closed circuit with the primary cyclone cluster. The 14 MW ball mill (7.32 m diameter x 12.8 m EGL) will be fitted with a fixed speed twin pinion drive arrangement. The ball mill product will overflow onto a trommel screen, oversized scats will feed an adjacent ball mill scats bunker and undersize slurry will gravitate into the cyclone feed hopper.

SAG and ball mill grinding media will be transferred from their individual storage bunkers into kibbles via a ball loading chute. A ball loading hoist will be used to lift the kibble and discharge the grinding media into each mill’s ball loading hopper. A ball feeder will transfer media at a controlled rate to the mill feed chute.

The Corani process plant is a two-stage sequential flotation concentrator generating separate lead (with silver) and zinc concentrates.

The design treatment rate for the process plant is 27,000 t/d based on operating 365 days per year. The operating basis for design is 70% availability for the crushing circuit, 92% availability for the grinding and flotation circuits, and 82.8% availability for concentrate and tailings filtration. The process plant includes the following unit processes and facilities:

• primary crushing
• stockpile and reclaim
• grinding and classification
• flotation and regrind
• concentrate thickening and filtration
• tailings thickening
• tailings filtration and stockpile
• reagents
• air and water services.

Ore will be crushed using a gyratory crusher. Crushed ore will be discharged to a single conical
coarse ore stockpile via conveyors. The grinding circuit will consist of a semi-auto ........